Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
High Wing Vs. Low Wing Aircraft  
User currently offlineRockyRacoon From United States of America, joined Oct 2003, 974 posts, RR: 0
Posted (10 years 9 months 2 weeks 6 days 11 hours ago) and read 18199 times:

What are the pros and cons of a high winged aircraft compared to a low winged plane? Feel free to correct me, but high winged craft generally offer better take off performance and offer the pilot a better view of the ground. Not sure of the low wing pluses, but they must out number the minuses for they dominate the skies. Am I totally off course or have the general idea?

Thanks in advance,

Tim

23 replies: All unread, jump to last
 
User currently offlineNormalSpeed From , joined Dec 1969, posts, RR:
Reply 1, posted (10 years 9 months 2 weeks 6 days 8 hours ago) and read 18161 times:

In my opinion, there really aren't really any substantial differences (although there are some more subtle ones that I will discuss in a minute). They are both airplanes, and you utilize the the same techniques to fly them.

I don't know that a high-winged airplane is necessarily better-performing at takeoff, at least by virtue of it being a high-wing airplane alone. Although, many short-field airplanes happen to be high wing, because that configuration seems to be more advantageous to rough-field operations (although you could, probably, find someone who would disagree.)

Let's see, the high-wing type that I have the most time in is the Cessna 172. The low-type that I have the most time in the Piper Arrow. It's my opinion that the Arrow is actually easier to land than the 172. I'm not sure exactly why this is, but I've heard that it has something to do with ground-effect being stronger, as the low wings are closer to the ground. Perhaps someone else could comment on this.

Which do I prefer? I like airplanes, period.


View Large View Medium
Click here for bigger photo!

Photo © Aaron 747



View Large View Medium
Click here for bigger photo!

Photo © Tony Zeljeznjak




-Normal


User currently offlineFutureualpilot From United States of America, joined May 2000, 2602 posts, RR: 8
Reply 2, posted (10 years 9 months 2 weeks 6 days 8 hours ago) and read 18141 times:

High wing aircraft tend to be more inherently stable than low-wing aircraft, however I believe most aircraft are low-wing because of weight and stress issues on the airframe.(The military cargo planes being a strong exception....the C-5s, C-17s, C-141s and C-130s are all AMAZING aircraft).




Life is better when you surf.
User currently offlineVikkyvik From United States of America, joined Jul 2003, 10027 posts, RR: 26
Reply 3, posted (10 years 9 months 2 weeks 6 days 7 hours ago) and read 18131 times:
Support Airliners.net - become a First Class Member!

The ground effect would indeed be stronger for low-winged airplanes, simply because the wings are closer to the ground. The ground effect reduces the induced drag (drag due to the wingtip vortices) on the airplane. The equation I'm familiar with for the coefficient of ground effect is:

ge = ((16h/b)^2) / (1+(16h/b)^2)

which is an approximation. h is the height of the wing above the ground, and b is the wingspan. This coefficient is multipied by the standard induced drag equation to yield induced drag at low altitudes. As an example:
For a wing that's 15 feet in the air with a 50 foot wingspan, ge = 0.958
For a wing that's 30 feet in the air with a 50 foot wingspan, ge = 0.989
So induced drag is about 3% lower if the wing is at 15 feet. As far as why low or high wings on particular planes, I have no idea about structural reasons.
~Vik



"Two and a Half Men" was filmed in front of a live ostrich.
User currently offlineLiamksa From Australia, joined Oct 2001, 308 posts, RR: 0
Reply 4, posted (10 years 9 months 2 weeks 6 days 7 hours ago) and read 18110 times:

A high-wing aircraft has gains in lateral stability due to the pendulum effects. I've heard that the tradeoff between stability and controllabilty is what leads to some high wing aircraft utilising an anhedral setup to regain some of that controllability. Anyone know for sure?


View Large View Medium
Click here for bigger photo!

Photo © Sigurdur Benediktsson
View Large View Medium
Click here for bigger photo!

Photo © Ben Pritchard



User currently offlineVikkyvik From United States of America, joined Jul 2003, 10027 posts, RR: 26
Reply 5, posted (10 years 9 months 2 weeks 6 days 5 hours ago) and read 18074 times:
Support Airliners.net - become a First Class Member!

Liamksa,
Indeed, the dihedral on a low-winged aircraft does make it laterally (if that's the right term) stable. In response to yaw or roll angles with respect to the flow direction, the plane will automatically return to steady flight at no yaw or roll angle due to the wings (for roll) and tail (for yaw). It seems to me that an anhedral would do the opposite, as in, if in a roll, the anhedral would cause the plane to continue rolling. However, someone else may know better.
~Vik



"Two and a Half Men" was filmed in front of a live ostrich.
User currently offlineL-188 From United States of America, joined Jul 1999, 29799 posts, RR: 58
Reply 6, posted (10 years 9 months 2 weeks 6 days 4 hours ago) and read 18061 times:

Well, High winged aircraft let you see the ground, keep you dry in the rain, and easy access to the fuel tank sumps generally.

Low winged aircraft, get into ground effect faster(great for soft field T/O's), don't block the upward view and don't require a ladder for fueling.

As mentioned above, there is a pendulum effect with a high wing aircraft that helps stabilize it. All pilots realize that C/G and C/L can be measured down the length of the aircraft. Most know that both can be measured left to right. Fewer realize that it can also be Measured on a vertical plane. With the C/G below the C/L it does act as a pendulum to level the plane out. The Dihedral helps the aircraft return to straight and level. With the cabin below, there is less need for the aerodynamic "assist" to return it to level fight.

As also noted on large high winged transports you tend to see Anhedral. And as correctly noted this is done to counter the "pendulum effect" (somebody got a proper name for this?). Picture a C-5 of a C-17 with a 60 ton M-1 Abrams main battle tank in the hold.

The C/G of the airplane with that tank is pretty far below the C/L of the wing. The Anhedral, which causes a tendency for a bank to steepened, is used to give enough, "oomph" to get that airplane banked into the corner. This is because of the amount of weight sitting below the C/L has a great effect on the aircraft.



OBAMA-WORST PRESIDENT EVER....Even SKOORB would be better.
User currently offlineKay From France, joined Mar 2002, 1884 posts, RR: 3
Reply 7, posted (10 years 9 months 2 weeks 6 days ago) and read 18037 times:

On the c172 the wings are going upwards. It was my understanding that they only go upwards by so much as opposed to a low wing where the wings point upwards much more, the reason for that being that, on low wing aircraft, if the plane is "slipping" sideways in a bank, the wing that is currently the low one in that particular bank will have more lift than the wing that is high, because it will be more horizontal thanks to this angle, it will therefore "resist" the bank and bring the plane back level, making for extra stability. I thought this was called the dihedral effect. On a high wing aircraft, the fact that there is a cabin hanging down between the wings (as opposed to the flat area between the wings on a low wing aircraft) greatly undermines the dihedral effect because the airflow/wind comes and gets stuck in the angle formed by the wing and the cabin (at the region of the cabin door on the c172), thus inherently resisting that "sideways slip" that all this is about. Because of this, dihedral is less on high wing aircraft, and so the upward angle formed by each wing is much less than that of low wing aircraft.

other theories state that high-wing offers better short-field performance and slower speeds in general.

I do not know about the heavy cargo/military high-wing planes, but it sounds like a good explanation that the wings point downwards, on the contrary of the above, to encourage banks, because CG is much lower than CL and it really matters and paralyzes the aircraft when the loads become heavy.

kay


User currently offlineSevenair From United Kingdom, joined Feb 2001, 1728 posts, RR: 0
Reply 8, posted (10 years 9 months 2 weeks 5 days 21 hours ago) and read 18006 times:

I fear that in a high wing, if you ditch, the cabin will immediately fall under the water, In a low wing, on the safety cards, you see people shimmying down the wong-boarding lifeboats, however not sure as the the procedure in high wing planes

User currently onlineGordonsmall From UK - Scotland, joined Jun 2001, 2108 posts, RR: 21
Reply 9, posted (10 years 9 months 2 weeks 5 days 21 hours ago) and read 18003 times:

In a low wing, on the safety cards, you see people shimmying down the wong-boarding lifeboats, however not sure as the the procedure in high wing planes

I'm always skeptical about reading safety cards, with their lovely pictures of 747's floating nicely on the top of the water, but as far as I'm concerned a 747 will float about as well as a boat flies.

I'm pretty sure it would float for a few minutes, maybe a bit longer but certainly isn't going to be around for hours - there are too many crevices for water to flow into. Although if the cabin was still pressurised I imagine it would float for quite a considerable time, though whether I would feel safer sitting in a pressurised cabin bobbing up and down on the sea or with doors open and diving into shark infested waters is best left until I cross that bridge.  Smile/happy/getting dizzy

Apart from everything else landing a large aircraft on water is bound to cause a lot of structural damage, just look at the Ethiopian 767 that had to ditch, it was torn to pieces when it hit the water (admittedly the wingtip hit the water first, but how many pilots are 100% sure they could land it wings level in a similar situation?). So IMHO whether it's a high wing or low wing aircraft is pretty academic - either way if you survived you want to be getting out pretty quickly, and if you didn't don't worry about it, you're dead anyway.  Smile/happy/getting dizzy

In the case of a light aircraft you've probably got a slightly better chance depending on where you went down, if you ditched off the coast of Greenland in the middle of winter the chances are you'll freeze to death before anyone even realises you've gone down - but if you put her on the water off the coast of England you would probably survive as you could be picked up relatively quickly.

Just my opinion.

Regards,
Gordon.



Statistically, people who have had the most birthdays tend to live the longest.
User currently offlineFredT From United Kingdom, joined Feb 2002, 2185 posts, RR: 26
Reply 10, posted (10 years 9 months 2 weeks 5 days 19 hours ago) and read 17981 times:

High wing aircraft are more stable laterally, which in some cases is countered by anhedral. It is not due to a pendulum effect though. Think about it. You have one lifting force, acting perpendicular to the wing through the centre of gravity. How could that roll the aircraft?

Instead, picture the airflow around the fuselage as the aircraft is in a slip. The airflow splits to go over and under the fuselage. With a high wing, the downgoing airflow will impact the the leeward wing, reducing the AoA and the lift and thus roll the aircraft away from the direction of slip. On the windward side, the opposite will happen with the upgoing airflow.


The main disadvantage of a high wing is in the structure. With a low wing design, the fuselage rests on the wing spar while with a high wing, the fuselage hangs off the wing spar. In the latter case, you have to reinforce the middle of the fuselage to transfer the loads. The wing section of the fuselage also has to carry the weight of the wing, engines, wing tank fuel and possibly the wing mounted landing gear in case of a crash. You do not want the wing coming down through the fuselage if you have to belly land the aircraft!

A low wing aircraft will have the wing spar/box under the floor, dividing the cargo area in two. A high wing aircraft has the eternal problem of having the wing spar/box either on top of the fuselage, creating drag, or through the top of the cabin, reducing internal space and making the perfect obstacle for pax and F/As to hit their heads on.

Then you can go with wing mounted landing gear which means long struts and excess weight. If you go with body gear, it will be narrow and use fuselage space or require draggy external pods. With body gear, the fuselage will again have to transfer the weight of the wings, engine and so on on every landing and all the time the aircraft is on the ground.


High wing means better ground clearance which means better rough field capabilities which makes it the design of choice for aircraft intended for rough and short strips. Thus, most aircraft with short takeoff runs are high wing designs.

It also means not having to waste as much lift generating top surface area to mount engines, which means that the same span wing will generate more lift.

Cheers,
Fred





I thought I was doing good trying to avoid those airport hotels... and look at me now.
User currently offlineVikkyvik From United States of America, joined Jul 2003, 10027 posts, RR: 26
Reply 11, posted (10 years 9 months 2 weeks 5 days 18 hours ago) and read 17945 times:
Support Airliners.net - become a First Class Member!

FredT,
From what I've been taught, it is a dihedral that provides lateral stability. I'm not quite sure how a high wing would influence that, given that most high wings are either flat or anhedral. It seems to me that a high wing would provide lateral stability based on what has (in this thread) been called the "pendulum effect" (I'm not familiar with the term, but I think I understand what they mean). Also, I couldn't quite understand your explanation of the slip factor. First, is slip a yaw, pitch, or bank angle? I thought it was yaw, but I can't remember. Thanks in advance for your comments.
~Vik



"Two and a Half Men" was filmed in front of a live ostrich.
User currently offlineLiamksa From Australia, joined Oct 2001, 308 posts, RR: 0
Reply 12, posted (10 years 9 months 2 weeks 5 days 8 hours ago) and read 17889 times:

High wing aircraft are more stable laterally, which in some cases is countered by anhedral. It is not due to a pendulum effect though. Think about it. You have one lifting force, acting perpendicular to the wing through the centre of gravity. How could that roll the aircraft?

In the case above there is no desire for a roll - the lifting force acting acting perpendicular to the wing through the centre of gravity indicates wings level. However following a disturbance in roll pendulum effects DO come into play and will attempt to restore a high-wing aircraft to level flight (lateral stability).

Imagine a 172 viewed from behind is disturbed by a gust, lifting the port wing. This results in the CoG being displaced towards the high-wing side and creates a moment about the CL opposite to the direction of the disturbance - ie: a restoring moment. So you could imagine in the case above with a 60 ton tank in the belly of the C-17 and any significant vertical distance between the CoG and CL the result will be quite a large moment opposite to the direction of the desired turn - hence the use of anhedral.

Given the same disturbance in a warrior - this time however the CoG (being above the CL) will be displaced towards the low-wing side, creating a moment about the CL in the direction of the original disturbance - ie: strengthening the roll towards the lower wing. Hence the use of larger angles of dihedral on low-wing aircraft.

It's harder to explain without diagrams but pendulum effects definitely increase the lateral stability of high-wing aircraft. Sometimes so much so that desired levels of controllability are lost. Fred?  Big grin

Cheers, Rob.


User currently offlineUSAFHummer From United States of America, joined May 2000, 10685 posts, RR: 52
Reply 13, posted (10 years 9 months 2 weeks 5 days 8 hours ago) and read 17878 times:

"...Ethiopian 767 that had to ditch, it was torn to pieces when it hit the water (admittedly the wingtip hit the water first, but how many pilots are 100% sure they could land it wings level in a similar situation?)."

...during that crash, the pilots were struggling for control with hijackers and thats why it crashed the way it did...had the pilots been undisturbed I think the aircraft would have survived a little bit better as they could put it down the way they wanted to...

Greg



Chief A.net college football stadium self-pic guru
User currently offlineBlatantEcho From United States of America, joined Sep 2000, 1913 posts, RR: 1
Reply 14, posted (10 years 9 months 2 weeks 5 days 7 hours ago) and read 17865 times:

I would also like to add that I believe the pilot was finally shot in the head just before impact, as a result of that struggle. Remember reading that in some report or another.

Not fun........


Didn't see it mentioned, but past single engine, engines are typically mounted on wings. Low wings = low engines, increasing the risk of FOD. (see 737 300/400/500)

George



They're not handing trophies out today
User currently offlineFredT From United Kingdom, joined Feb 2002, 2185 posts, RR: 26
Reply 15, posted (10 years 9 months 2 weeks 4 days 13 hours ago) and read 17805 times:

Vikkyvik,
slip to me means flying with a beta angle. Slip or skid, I use them interchangeably. Others insist on them being separate creatures, yet again others differentiate between slips and forward slips.

Liamksa,
the CoG displacement theory you describe above depends on a vertical acceleration field. On ground-mounted structures, that acceleration field is gravity. You do not have such a field in an aircraft, where all acceleration comes from aerodynamic forces (although you better counter the acceleration caused by gravity with aero forces if you want to remain airborne for any length of time). Instead, you have a local acceleration which is more or less perpendicular to the wings.

Yes, dihedral does provide lateral stability. No argument there. High wings provide lateral stability as well, and thus the anhedral of e g the BAe 146 and some other high-wing aircraft.

However, the pendulum effect isn't. A pendulum aligns itself with the acceleration it, or rather its mounting point, is subjected to. As I said, the acceleration on an aircraft in flight is largely perpendicular to the lateral (y) axis or, in other words, the wings. Thus, the pendulum effect will align the fuselage to be directly below the point on the wing at which it is mounted. If it is dislocated from that point in the first place, you have larger problems than lateral stability. Looking for parachutes would probably be a good starting point.  Smile

Cheers,
Fred



I thought I was doing good trying to avoid those airport hotels... and look at me now.
User currently offlineJetguy From , joined Dec 1969, posts, RR:
Reply 16, posted (10 years 9 months 2 weeks 4 days 6 hours ago) and read 17771 times:

High wing vs. low wing is an argument that has been going on since shortly after the Wright brothers first flight. As the posts above indicate, there are theoretical advantages and benefits to each design. Just to muddy the water, I'm an Aerostar fan and happen to like mid-wing designs.

The military chooses high wing designs to facilitate the loading of cargo. The high wings never caught on in the airline world, although Lockheed did get FAA certification for the C-141 and (I believe) nearly completed the certification process for the C-5; however, no airlines purchased the aircraft and the projects were dropped. One of my FlightSafety sim instructors is a retired USAF C-5 pilot with a civilian C-5 type rating - it was issued to him based on his military experience, immediately prior to the cancellation of the project. I believe that Boeing also got civilian certification of the C-17 with the hope that one of the cargo carriers would bite. It didn't happen.

As far as "real world" comparisons between the two aircraft, you'd have to be a better pilot than me to tell the difference. I believe that if it were possible to place identical generic cockpits in a low wing aircraft and a high wing aircraft it would be nearly impossible to tell any difference between the two. Most pilots seem to have their opinions, but they all seem to be based on esthetics and personal preferences. It's like arguing over who are more beautiful - blondes or brunettes (or redheads). Since my wife is watching me as I type this the correct answer is brunettes. Ouch, she just hit me.

Jetguy


User currently offlineEmiratesA345 From Canada, joined Jun 2003, 2123 posts, RR: 8
Reply 17, posted (10 years 9 months 2 weeks 4 days 4 hours ago) and read 17757 times:

One advantage of the high wing aircraft is visibility.

EmiratesA345 Smile/happy/getting dizzy



You and I were meant to fly, Air Canada!
User currently offlineKay From France, joined Mar 2002, 1884 posts, RR: 3
Reply 18, posted (10 years 9 months 2 weeks 3 days 21 hours ago) and read 17738 times:

FredT, Jetguy, Normal, all

when they first bought in a shining-new Piper PA28 at the flying school neighboring mine, I remember the discussions were all around about the differences it had with the equivalent Cessna, the C182. The most noticeable were these:

- it feels much more like "real flying" because of the low-wing design. It is closer to an airliner than a c182 is, also partly because of the throttle controls that are between the seats.
- at idle-engine, it does not glide at all but *falls*. I remember this one marked me because they were discussing an incident about one guy who, while practicing for the approach to land, took out power, and got so surprised by the sudden rate of descent he kinda came close to having a disaster...

so what's real about the piper 28 or low-wing in general... According to this discussion, the two points above don't seem to be that accurate. One thing seems to be true though, high-wing aircraft seem to accomodate low speed operations better..

kay


User currently offlineJetguy From , joined Dec 1969, posts, RR:
Reply 19, posted (10 years 9 months 2 weeks 3 days 2 hours ago) and read 17673 times:

Kay...
You mustn't make the mistake of comparing apples and oranges. There are many variables that enter into the "aircraft handling" equation such as wing loading, power loading, etc., etc., etc. There are very docile high-wing aircraft (any Cessna SEL) and there are those that will really bite you if given the chance (BD-4). Dittos, for the low-wing crowd. If you compare aircraft that are designed to accomplish a comparable mission they will tend to have comparable performance and characteristics - Take, for example the Cessna 182 and the Piper PA-28-235. Their ain't a nickel's difference between them. Same goes for the Cessna 172 and the PA-28-160. If you move up in size to bizjets or airliners the same idea still applies. Airplanes are little more than flying compromises.

Jetguy


User currently offlineBMAbound From Sweden, joined Nov 2003, 660 posts, RR: 4
Reply 20, posted (10 years 9 months 2 weeks 19 hours ago) and read 17575 times:

One thing is for sure. I'd rather ditch a low-winged A/C with retractable gear than for example a 172!

However, I have to say I like high-winged A/C's better. Can't tell you why really, just a "thing"...

johan



Altitude is Insurance - Get Insured
User currently offlineAlessandro From , joined Dec 1969, posts, RR:
Reply 21, posted (10 years 9 months 2 weeks 10 hours ago) and read 17538 times:

If you after STOL preformance (Fieseler-Storch or An-72) or extremely heavy planes (AN-225) use high wing , if you´re after good flight economics use low wings.


User currently offlineFlyPIJets From United States of America, joined Oct 2003, 912 posts, RR: 2
Reply 22, posted (10 years 9 months 1 week 6 days 19 hours ago) and read 17492 times:

With respect to the C-172 /PA-28 high wing / low wing issues.

The low wing a/c will require a fuel pump(s) and the high wing will use gravity to feed the engine its fuel. As long as they have a carb.

This adds weight and the possibility of vapor lock to the low wing a/c.



DC-8, DC-9, DC-10, F28, 717, 727, 737, 747, 757, 767, IL-62, L-1011, MD-82/83, YS-11, DHC-8, PA-28-161, ERJ 135/145, E-1
User currently offlineBMAbound From Sweden, joined Nov 2003, 660 posts, RR: 4
Reply 23, posted (10 years 9 months 1 week 5 days 16 hours ago) and read 17454 times:

"...I would also like to add that I believe the pilot was finally shot in the head just before impact, as a result of that struggle. Remember reading that in some report or another..."



I saw an interview with the captain, don't know about the the F/O though

johan




Altitude is Insurance - Get Insured
Top Of Page
Forum Index

Reply To This Topic High Wing Vs. Low Wing Aircraft
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
Most Suitable/efficient Low Fare Aircraft posted Mon Feb 6 2006 17:14:17 by Curious
Minimum Fuel Vs. Low Fuel posted Sat Dec 2 2000 19:25:57 by A7700
Low Vs High Wing Aircraft posted Sat Jul 6 2002 07:53:47 by Trent_800
High/Low Wing Aircraft Advantages/disadvantages posted Mon Mar 27 2006 22:46:21 by Hcpunx99
Nose High Vs. Nose Low Approaches posted Wed Mar 22 2006 03:57:47 by FlyingNanook
Aircraft Edge Of Wing Lights posted Thu Jul 14 2005 20:17:34 by Jetset7E7
Clean Wing Vs. Cluttered Wing posted Tue Dec 28 2004 15:48:34 by Thrust
Pilot Positions Helicopter Vs Fixed Wing posted Tue Jul 6 2004 17:51:32 by NORTHSEATIGER
Wing Tip Strobes On Passenger Aircraft.. posted Wed Feb 11 2004 19:17:30 by AA777-200
737NG Vs Classic Wing Sweep posted Wed Jun 5 2002 20:30:17 by Barney captain

Sponsor Message:
Printer friendly format